What is a stroke?

2The Stroke Association

The following leaflets are available in this series.

The Stroke Association

What is a stroke?

Preventing a stroke

When a stroke happens

After a stroke

Stroke rehabilitation

The Stroke Association also produces factsheets on specific stroke issues. To find out how to orderleaflets or factsheets, or for more information onstrokes, phone 0845 3033 100, emailinfo@stroke.org.uk or visit our website atwww.stroke.org.uk.

We distribute two million free leaflets and factsheetsevery year. Help us to continue this vital service bymaking a donation on our website or by phoning01604 623943. If you have any complaints aboutThe Stroke Association, please contact usimmediately on 0115 8402683. We will happilydiscuss and try to sort out any problems.

The Stroke Association is registered as a company limited by guaranteein England and Wales number 61274. Registered charity number 211015and registered charity in Scotland number SC037789. Copyright © The Stroke Association June 2008

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Every year, an estimated 150,000 people in the UKhave a stroke. That�s one person every five minutes.Most people affected are over 65, but anyone can havea stroke, including children and even babies. Around1000 people under 30 have a stroke each year.

A stroke is the third most common cause of deathin the UK. It is also the single most common cause of severe disability. More than 250,000 people in theUK live with disabilities caused by a stroke.

It could happen to you, or someone you care for. If it does, you�ll want to know as much as you canabout strokes. This leaflet explains what a stroke is,what causes it, and some of the physical andpsychological effects it can have on people�s lives.

What is a stroke?

‘I was having a great day at work andnothing seemed unusual. Suddenly the lightswent out. Seven hours later I woke up inhospital. I couldn’t move my right side, andmy speech had gone.’ David Diston

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A stroke is a brain injury caused by suddeninterruption of blood flow.

The Stroke Association

A stroke is a brain attackA stroke is what happens when the bloodsupply to part of the brain is cut off.

Blood carries essential nutrients and oxygen to the brain. Without a blood supply,brain cells can be damaged or destroyedand won�t be able to do their job.

Because the brain controls everything the body does,damage to the brain will affect body functions. Forexample, if a stroke damages the part of the brain that controls how limbs move, limb movement will be affected.

The brain also controls how we think, learn, feeland communicate. A stroke can also affect thesemental processes.

A stroke is sudden and the effects on the body are immediate.

InfarctionStroke can cause brain tissue to die, and this is calledcerebral infarction. An infarct is an area of dead tissue.It can be tiny or affect a larger part of the brain.

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Blood flow to the brain can be cut off by:

� a blockage (ischaemic stroke); or

� a bleed (haemorrhagic stroke).

What is a stroke?

There are two main causes of stroke

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The most common type of stroke (over 80% of cases) iscaused by a blockage. This is called an ischaemic stroke,which happens when a clot blocks an artery that carriesblood to the brain. It may be caused by:

� a cerebral thrombosis, when a blood clot (thrombus) forms in a main artery to the brain;

� a cerebral embolism, when a blockage caused by a blood clot, air bubble or fat globule (embolism)forms in a blood vessel somewhere else in the bodyand is carried in the bloodstream to the brain; or

� a blockage in the tiny blood vessels deep within the brain (lacunar stroke).

The second type of stroke (up to 20% of cases) is caused by a bleed, when a blood vessel bursts, causing bleeding(haemorrhage) into the brain. This is called a haemorrhagic stroke. It may be caused by:

� an intracerebral haemorrhage, when ablood vessel bursts within the brain; or

� a subarachnoid haemorrhage, when a blood vessel on the surface of the brain bleeds into the area between the brain and the skull (subarachnoid space).

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A stroke is a medical emergency.

If you see the signs of a stroke, act FAST and call 999.

The sooner someone receives treatment, the bettertheir chance of recovery.

The Stroke Association

Use the Face–Arm–Speech Test (FAST)Three simple checks can help you recognise whether someonehas had a stroke or mini-stroke (transient ischaemic attack � TIA).

Facial weakness: Can the person smile? Has their mouth oran eye drooped?

Arm weakness: Can the person raise both arms?

Speech problems: Can the person speakclearly and understand what you say?

Test these symptoms. If you see any ofthese signs, call999 immediately.

Common symptoms of a strokeThe first signs that someone has had a stroke arevery sudden. Symptoms include:

� numbness, weakness or paralysis on one sideof the body (signs of this may be a drooping arm,leg or lower eyelid, or a dribbling mouth);

� slurred speech or difficulty finding words or understanding speech;

� sudden blurred vision or loss of sight;

� confusion or unsteadiness; and

� a severe headache.

F

A

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Transient ischaemic attack (mini-stroke)A transient ischaemic attack (TIA), often called a mini-stroke, happens when the brain�s blood supplyis interrupted for a very brief time.

The symptoms are very similar to a stroke (such asweakness on one side of the body, loss of sight andslurred speech) but they are temporary � lasting a few minutes or hours, and then disappearingcompletely within 24 hours.

In a TIA, the affected part of the brain iswithout oxygen for just a few minutes. A TIA is a sign that part of the brain is notgetting enough blood and that there is a risk of a more serious stroke in the future. So, you should not ignore signs of a TIA � getmedical help as soon as you can.

7What is a stroke?

Never ignore a TIA (mini-stroke). It’s a warning sign.

‘I was walking to work and I lost the feeling inone leg, and I sort of collapsed. The followingyear, walking to work, I suddenly went blind inone eye. I stood still for five minutes to work out what was going on.’ Claire Simpson

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SexIn people aged under 75, more men have strokes than women.

AgeStrokes are more common in people over 55, and the risk continues to rise with age. Arteries harden and become �furred up� by a build-up of cholesteroland other debris (atherosclerosis) over many years.

Family historyHaving a close relative who has had a stroke increasesthe risk, possibly because conditions such as highblood pressure and diabetes tend to run in families.

Ethnic backgroundPeople from Asian, African and African–Caribbean

communities are at greater risk of having a stroke.Medical conditions like diabetes and high blood pressureare also more common in people from these communities.

A stroke can happen to anyone, but some people are more at riskA stroke can happen with no obvious cause to people of any age � but there are factors known to increase the likelihood of ithappening. Some of these factors are things that can’t be changed.Other risks may be reduced by lifestyle changes or medication.

‘At 29 I had my first stroke, I made a fullrecovery and doctors dismissed it as a one-off.But two years later it happened again. Thistime it was worse. I lost both sight and speechand I couldn’t stand.’ Brad Francis

What cannot be changed

The Stroke Association

9What is a stroke?

Smoking doubles your risk of having a stroke. The NHSSmoking Helpline can helpyou give up, phone 0800 022 4 332, or visitwww.gosmokefree.nhs.uk.

Medical conditionsIf they are not treated, over time theseconditions may damage the arteries.

� High blood pressure (hypertension)

� Heart disease and irregular heartbeat (atrial fibrillation)

� Diabetes

� Other rare medical conditions, including blood-clotting disorders such as Hughes Syndrome.

Diet � a diet high in fatty foods causes cholesterolto build up in the blood and the rteries to narrow. Toomuch salt can lead to high bloodpressure. Being very overweight(obese) puts extra strain on the heart.

Too much alcohol � regular heavydrinking raises blood pressure. Bingedrinking (drinking a lot of alcohol in ashort time) can cause a blood vessel inthe brain to burst.

Exercise � an inactive lifestyle cancontribute to furring of the arteries.Regular exercise helps keep the heart and bloodstream healthy.

Reduce your risk� Have your blood

pressure checkedregularly.

� Stop smoking.

� Take regular exercise.

� Avoid heavy drinking.

� Cut down on salt andfatty foods.

� Eat plenty of fruit andvegetables.

What the doctor can help with

What we can do to help ourselves

SmokingSmoking causeshigher blood pressureand makes the bloodthicker. The chemicalsin tobacco smoke areabsorbed into thebody, damaging bloodvessel walls.

10The Stroke Association

A stroke causes damage to the brain,which affects how the body worksBecause a stroke is a brain injury, the effects, or symptoms, will depend on the part of the brainthat is affected.

Every stroke is different and people who have a stroke are affected in different ways. For some, the symptoms are quite mild and last a short time(just a few minutes or hours in the case of a TIA or mini-stroke). Other strokes may cause more severeand lasting damage.

When a stroke happens, some brain cells aredamaged and others die. Dead brain cells can�t startworking again, but those just outside the area of thedead cells may recover as the swelling caused by the stroke goes down.

It�s also possible that other parts of thebrain can learn to take over from areas that have died. Most recovery happens in the first few months, but people cancontinue to recover for several years after the stroke.

‘He woke up in the night feeling sick. He sleptvery heavily. When we woke him he was semi-conscious, drowsy and sleepy. When the doctorarrived he took one look at him and decided toget him to hospital.’ Jacob Goodier was onlythree when he had a stroke.

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Different parts of the brain controldifferent parts of the bodyThe right half of the brain controls the leftside of the body and vice versa. Commonsymptoms like weakness in parts of the body or not being able to use an arm or leg(paralysis) happen on the opposite side ofthe body to the stroke side of the brain.

In most people, the left half of the brain is responsible for language (talking,understanding, reading and writing), and the right half is responsible for perceptual skills (making sense of what you see, hear and touch) and spatial skills (judging size, speed, distance or position in space).

What is a stroke?

Language problems are more likely if thestroke is in the left side of the brain, andproblems with perception are more likely if the stroke is in the right side of the brain.

The effects of a stroke will depend on:

� the part of your brain that has been injured;

� how bad the injury is; and

� your general health when the stroke happens.

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A stroke can cause loss of control over:� body functions (how the different parts

of the body work); and

� cognitive functions (mental processes like thinking, feeling and learning).

Weakness or paralysis Weakness, clumsiness or paralysis (hemiplegia) is one of the most recognisable and most common symptoms of a stroke. It usually happens on one side of the body.Weakness or paralysis of an arm or leg is often made worseby stiffness (spasticity) of the muscles and joints.

BalanceUnsteadiness (loss of balance) can be caused by damage to the part of the brain that controlsbalance. Or it may happen because of paralysisresulting in muscle weakness.

SwallowingAbout 50% of people havedifficulty with swallowingafter a stroke (dysphagia). This can be dangerous if food �goes down the wrong way� and gets into the windpipe.

Common problems after a strokeThere are several problems or disabilities strokesurvivors may face in the first few weeks afterhaving a stroke. Most of these will improveover time as the brain recovers. In severecases, they may cause long-term disability.

The Stroke Association

All stroke patients have a swallow test inhospital and are onlyallowed to drink and eatwhen it is shown theycan swallow. Somepeople may need fluidthickeners and help witheating for a while.

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‘John had just got in from work, and I asked him something. He answered me with agarbled response. I realised immediatelythat it was a stroke.’ Susie’s husband John had a stroke five years ago.

What is a stroke?

Sleep and tirednessMost people suffer from extreme tiredness (fatigue) in the first few weeks after a stroke. Many also havedifficulty sleeping, which makes them even more tired.

Speech and languageMany people experience problemswith speaking and understanding,and with reading and writing. This difficulty with language iscalled aphasia.

When a person finds it hard tounderstand what is being said, it is called receptive aphasia.Sometimes a person may understand what is being said but can’t find the right words to express what theywant to say � this is called expressive dysphasia.

People often have a mixture of both types of aphasia.

Aphasia is most commonwith strokes that damagethe left side of the brain.

The exception is in someleft-handed people whoselanguage area is on the right side of their brain.

14The Stroke Association

Stroke risk is much higher for people who havehad a stroke or TIA (mini-stroke) before. About10% of people who have had a stroke will haveanother one in the first year.

EyesightA stroke can damage the parts of the brainthat receive, process and interpret

information that the eyes send. Sometimes,people who have had a stroke may have double

vision or lose half of their field of vision � they cansee everything over to one side but are blind onthe other. This can cause clumsiness andseemingly odd behaviour (like not eatingfood on one side of a plate).

Perception and interpretingPeople may have difficulty recognising familiar objects or knowing how to use them. They may alsohave problems with skills like telling the time if the brain can�t interpret what the eyes see.

Mental processesA stroke often causes problems with mentalprocesses such as thinking, learning, concentrating,remembering, making decisions, reasoning andplanning. People may lose short-term memory, whichmakes it difficult to pay attention and concentrate.

Bladder and bowelsDifficulty controlling the bladder and bowels(incontinence) is not unusual after a stroke. Most people regain control in a few weeks.

15What is a stroke?

The symptoms of a second stroke can be asvaried as the first – it’s unlikely that exactlythe same part of the brain will be affected.

Mood swingsEmotional ups and downs are very likely after a stroke. Depression, sadness, anger, anxiety, low self-esteem and loss of confidence are common.

Sometimes, people find it hard to control theiremotions and may cry, swear or laugh at inappropriatetimes. They may find that their inhibitions are lifted andtheir behaviour seems out of character.

SensationSome people have problems with sensation � they feeltoo much or too little. They may be very sensitive tocolour, sound and light. Or they may not feel painfulsensations like heat or sharp objects which can cause accidents and injuries.

PainPain can be caused by the stroke (for example, shoulder pain and spasticity), or may be caused by problems the person had before the stroke being made worse.

Recovering from a stroke takes timeAfter an initial spurt of recoveryin the first few weeks, the mendingprocess is very gradual. It may take more than a year before the person has made the bestpossible recovery, and some people continue to improveover a much longer period.

Every five minutes someone in the UK has a stroke.A stroke doesn�t discriminate. It can happen toanyone at any time in their life. Strokes are suddenand their consequences can be devastating.

The Stroke Association is the only UK charity solelyconcerned with helping everyone affected by stroke.Our vision is to have a world where there are fewerstrokes and all those touched by stroke get the helpthey need.

Stroke Helpline: 0845 3033 100

Website: www.stroke.org.uk

Registered office:The Stroke AssociationStroke House240 City RoadLondon EC1V 2PR.

Email: info@stroke.org.uk

Textphone: 020 7251 9096

The Stroke AssociationWorking for a world where there arefewer strokes and all those touched by stroke get the help they need.

The Stroke Association is a UK-wide organisation with offices

in Scotland, Wales, Northern Ireland and the nine English regions.

You can find more contact information on our website.

What is a stroke? (2)